The instructions are poorly written! The folder locations are wrong as well!
Replace
/Applications/DaVinci Resolve/DaVinci Resolve.app/Contents/Libraries/
/Library/Application Support/Blackmagic Design/DaVinci Resolve
It should be:
Replace “Resolve” to
"/Applications/DaVinci Resolve/DaVinci Resolve.app/Contents/MacOS/“
"libfusionsystem.dylib” to:
"/Applications/DaVinci Resolve/DaVinci Resolve.app/Contents/Libraries/Fusion"
also
sudo xattr -cr
sudo codesign --force --deep --sign -
for both files